Power from Mine Cooling Water.
Power Eng 1986 Mar; 90(3):27-28
The U.S. Bureau of Mines, as part of its health and safety research program, funded a research program to study the applicability of energy recovery techniques to the mining industry. Since much of the electric power consumed in the United States is generated by converting the energy from falling water, it is easy to conceive that water flowing down long, vertical pipelines into deep mines could be utilized in a similar manner by allowing the high-pressure water to operate a turbine at the bottom of the pipeline. An energy recovery system of this type can offer several advantages. Modern turbines can convert about 90% of the water's potential energy into useful shaft work. In using a turbine with an efficiency rate of 85%, the temperature rise of the water due to potential energy conversion is only 15% of the rise experienced with no turbine. Lower water temperature resulting from turbine usage can be expressed directly in tons of refrigeration (which becomes important to cooling the working environment in deep mines).
Power Eng., V. 90, No. 3, Mar. 1986, PP. 27-28